Fishermen who use traps to catch their target species, such as crab or lobster, typically set their traps out for more than a day. Buoys are attached to the traps via a length of rope to facilitate retrieval for harvest at a later date, either a single trap per buoy, or multiple traps with one or more buoys. However, during the time that the traps are unattended, fisherman can lose their traps due to a variety of reasons. Trap fishing gear can be washed away by inclement weather conditions, abandoned, entangled by marine mammals, dragged under by current, stuck in sediment, or severed by vessel propellers. It is estimated that crab and lobster fishermen around the world often lose between 10-30% of their traps each season. Whether or not buoys remain attached to the trap via the buoy line may depend on how the trap became lost to the ocean environment. Over time, derelict trap fishing gear can have a potentially negative impact on the ocean environment and marine life. Derelict pots may continue to capture animals without being harvested, known as ghost fishing, which can decimate a fishery's stocks. Lost traps can damage the ocean floor, and buoys with lines attached may entangle a marine mammal, boat propeller, or other fishing gear. The longer derelict gear are left out at sea, the greater the potential damage.
Search, location, and retrieval methods for lost trap fishing gear are currently handled in a variety of ways. Buoys can be surveyed from the air or reported by other boats in the vicinity. Side-scan sonar or remotely operated vehicles are often used to conduct surveys of large areas prior to or in conjunction with retrieval efforts. These methods are both costly and time consuming, and most traps are found by chance over a large area. To disentangle a whale from fishing gear, special methods, skills, and equipment are required. When a whale is seen entangled in gear, it is often not sighted again, preventing rescue efforts from occurring.